    const http = require('http')
    const slice = Array.prototype.slice

    class LikeExpress {
      constructor() {
        // 存放中间件的列表
        this.routes = {
          all: [], // app.use(...)
          get: [], // app.get(...)
          post: [] // app.post(...)
        }
      }

      register(path) {
        const info = {}
        if (typeof path === 'string') {
          info.path = path
          // 从第二个参数开始，转换为数组，存入 stack
          info.stack = slice.call(arguments, 1)
        } else {
          info.path = '/'
          // 从第一个参数开始，转换为数组，存入 stack
          info.stack = slice.call(arguments, 0)
        }
        return info
      }

      use() {
        const info = this.register.apply(this, arguments)
        this.routes.all.push(info)
      }

      get() {
        const info = this.register.apply(this, arguments)
        this.routes.get.push(info)
      }

      post() {
        const info = this.register.apply(this, arguments)
        this.routes.post.push(info)
      }

      match(method, url) {
        let stack = []
        if (url === '/favicon.ico') {
          return stack
        }

        // 获取 routes
        let curRoutes = []
        curRoutes = curRoutes.concat(this.routes.all)
        curRoutes = curRoutes.concat(this.routes[method])

        curRoutes.forEach(routeInfo => {
          if (url.indexOf(routeInfo.path) === 0) {
            // url === '/api/get-cookie' 且 routeInfo.path === '/'
            // url === '/api/get-cookie' 且 routeInfo.path === '/api'
            // url === '/api/get-cookie' 且 routeInfo.path === '/api/get-cookie'
            stack = stack.concat(routeInfo.stack)
          }
        })
        return stack
      }

      // 核心的 next 机制
      handle(req, res, stack) {
        const next = () => {
          // 拿到第一个匹配的中间件
          const middleware = stack.shift()
          if (middleware) {
            // 执行中间件函数
            middleware(req, res, next)
          }
        }
        next()
      }

      callback() {
        return (req, res) => {
          res.json = (data) => {
            res.setHeader('Content-type', 'application/json')
            res.end(
              JSON.stringify(data)
            )
          }
          const url = req.url
          const method = req.method.toLowerCase()

          const resultList = this.match(method, url)
          this.handle(req, res, resultList)
        }
      }

      listen(...args) {
        const server = http.createServer(this.callback())
        server.listen(...args)
      }
    }

    // 工厂函数
    module.exports = () => {
      return new LikeExpress()
    }